What are PDF layers?
In a PDF, layers are separate, independent sections of content that can be stacked to create the final document. Layers are also called Optional Content Groups (OCGs) or simply "OCGs".
Each layer can contain different elements such as images, text, or annotations, and can be turned on or off, hidden or shown, and reordered. This lets users view and edit specific parts of a document without affecting the rest of the content.
Layers are often used in complex PDF documents such as technical drawings, maps, and diagrams to show different views or levels of detail, and in interactive PDF forms to display different form fields depending on user input.
